3D Printing With Polymers The Stereolithography Way
Stereolithography is a unique process of creating three-dimensional objects with a computer within a few hours. It is also called 3D printing, 3D layering or additive manufacturing.
It employs a novel technique to create a solid object in its entirety. The base is a drawing (CAD) and the computer uses the drawing to create the three dimensional object. The computer literally creates the object layer by layer and this is why it is also called additive manufacturing.
How it works?
A liquid polymer – like polyurethane resin or silicone rubber – forms the base for forming the solid plastic object.
The technician has to first design a CAD drawing of the desired object. The computer will then break up the CAD program into layers before ‘printing’ it on the material.
Indeed, the computer literally prints (or paints) the cross section pattern of the base of the object using the desired polymer in the vat. A thin layer is formed which quickly hardens when exposed to the computer-controlled laser beam. The computer again traces another layer of the object and the liquid polymer hardens quickly enough on laser contact.
In this way, successive slices are constantly added one on top of the other, till the entire structure of the object is formed and solidifies. It has to be rinsed, cleaned and baked for proper curing.
This 3D printing computer is called a stereolithograph apparatus (SLA). It takes a minute or so to print a layer and a medium sized object can be ready within 6 hours or so. Bigger and more detailed objects can even take days.
In fact, stereolithography is only one of the forms of 3D printing objects. But it is the most popular technique as it makes rapid prototyping possible. You no longer have to wait for months to see how your invention will actually shape out. A sample can be ready for your perusal within a matter of hours. Changes and improvements also pan out faster and better.
Even mechanical engineers take advantage of this technology to verify the form or fit of a part (say screw or even a door handle) before putting it into mass production. And so do medical and manufacturing industries. The best part is that the samples or parts always turn out accurate and are durable too. And it is not to expensive either.
Indeed, all you have to now do is physically visualize a product to be able to turn it into a tangible reality! Just fall back on 3D printing and let the computer software and its ultraviolet laser tools do the job on the silicones or polyurethanes. It is actually quite exciting to watch how the liquid silicones or polyurethanes are quickly converted into different kinds of solid objects right in front of your eyes! All it takes is a little more finishing and you are ready to go!